A controversial casino campaign already under investigation by the state agency that enforces election laws is about to get a new level of scrutiny from the Legislature.

The Government Oversight Committee voted unanimously Wednesday to gather information and hold a public hearing about a ballot campaign that, if approved by voters, would allow casino developer Shawn Scott — and only Scott — to hold a license for a casino in York County.

The campaign has already spent more than $4 million just to get on the ballot and it’s now ramping up a messaging and voter influence operation that will be run, in part, by the same Washington, D.C., firm hired to convince British voters to leave the European Union.

Members of the GOC committee said the campaign has been dogged by controversy and that the public should have a chance to hear more about the implications if voters approve it. GOC chairs Sen. Roger Katz, R-Augusta, and Rep. Anne-Marie Mastraccio, D-Sanford, said the review and hearing are designed to shed more light on the proposal.

“The suggestion of the chairs is to hold a public hearing with respect to this whole process and this particular initiative to shed light on what’s been going on,” Katz said. “Because, frankly, it smells.”

The casino initiative is under investigation by the Maine Ethics Commission, which oversees and enforces elections laws, because it obscured its funding sources for more than year. The commission is trying to dig into the funding sources, which currently link to a web of offshore and domestic investment firms. Some of the firms have direct ties to Shawn Scott, who first brought gambling to Maine when he financed a campaign that led to the racino and slots parlor in Bangor more than a decade ago.

Since then Scott has left a trail of litigation as he pursued other gambling ventures in the U.S. and overseas. He and his associates were also involved in a bid to build a gambling operation in Massachusetts last year. Voters defeated the proposal, but not before Scott’s associates obscured its involvement in financing the campaign. Massachusetts regulators eventually fined the campaign over $125,000 for hiding its funding sources.

Many of the same firms in the Massachusetts referendum are now involved in the campaign to convince Maine voters to let Scott license a casino at an undisclosed location in York County.

Katz and others on GOC said the information gathering effort and hearing won’t necessarily result in a formal investigation. However, the committee is using the Office of Program Evaluation and Government Accountability, or OPEGA, to compile facts about the initiative and its principal players. OPEGA is typically used to evaluate the effectiveness of government programs and is perhaps best known for its probe of the Maine Turnpike Authority — an inquiry that resulted in the conviction of its former director.

The GOC inquiry may also serve opponents of the casino initiative, which have yet to formally launch an organized campaign, but are expected to do so. The opposition is expected to include Churchill Downs, which operates the Oxford County Casino, and Penn National Gaming, which runs the Bangor racino and Hollywood Slots. The Bangor facility is the same operation Scott convinced voters to create over a decade ago. He later sold the license, earning a reported $52 million.

Sen. Bill Diamond, D-Windham, said the point of the GOC vote is to shed light on the casino campaign.

“It’s been pretty much behind the scenes. The Legislature’s talked about it in committees, but it really hasn’t been talked about for the public to take part in,” he said. “The purpose of this public hearing, public discussion, is to bring all of this to the forefront.”

Diamond was asked if the timing of the hearing — late October and a few weeks before voters go to the polls — is a concern.

“Frankly I think the timing is good. Too often we have seen referendums that are passed by the voters and they have little information to go on. This is a particularly interesting one and it could have repercussions for the state of Maine for quite a while,” he said.

Rep. Jeffrey Pierce, R-Dresden, voted for the GOC hearing. However, he later expressed concerns about singling out the casino referendum. Pierce is expected to ask for a separate review of the citizen initiative process, which lawmakers have repeatedly complained has been exploited by outside groups who use well-financed and sophisticated campaigns to pass legislation that can’t get enacted in the Legislature.